Efeito de fungicidas aplicados em diferentes estádios no controle da ferrugem asiática e na produtividade da soja [Glycine max (L.) merrill]

• Ano de defesa: 2006
• Autor(a) principal: Silva Júnior, Jorge da
• Orientador(a): Rezende, Pedro Milanez de
• Banca de defesa: Alves, Eduardo, Botrel, Élberis Pereira
• Tipo de documento: Dissertação
• Tipo de acesso: Acesso aberto
• Idioma: por
• Instituição de defesa: UNIVERSIDADE FEDERAL DE LAVRAS
• Programa de Pós-Graduação: DAG - Departamento de Agricultura
• País: BRASIL
• Palavras-chave em Português: Ferrugem da soja; Fungicidas; Épocas de aplicação; Controle químico; Chemical control; Application times; Soybean rust´s
• Área do conhecimento CNPq: CNPQ_NÃO_INFORMADO
• Link de acesso: https://repositorio.ufla.br/handle/1/4119

Currently, Brazil stands out as the second largest producer and the largest exporter of soy [Glycine Max (L) Merrill], and the productivity has had a significant increase in recent harvests, causing this culture to be of extreme importance for the economy of the country. The asian rust caused by the fungus Phakopsora pachyrhizi H. Sydow & R. Sydow is among the diseases that cause great damage to the Brazilian soybean farming. It could cause a fall in productivity from 50% to 80% with a month of infection and absence of treatment. The objective of this work was to verify the effect of the use of the fungicides chlorothalonil + thiophanate methyl (Cerconil PM®), chlorothalonil (Cercobin 700 PM®), thiophanate methyl (Daconil BR®), Copper Hydroxide (Blue Cupravit BR®), and pyraclostrobin + epoxiconazole (Opera®) at different application times. The pulverization was accomplished at the vegetative state V6 (before flowering), at the initial flowering stage (R1), initial stage of grain formation (R5), and also the times of combined stages V6 + R1, V6+R5 and R1+R5, in the control of the Asian rust and in the soybean productivity, also including a treatment without application of fungicides, using Conquista as a culture control. The evaluations were accomplished in three phases, at 15, 30 and 45 days after the first application. The experiment was sowed on November 15th in the agricultural year 2005/06 in the experimental area of DAG/UFLA, in Lavras, MG. The results obtained in this work permitted to conclude that the Asian rust was better controlled when the fungicide Opera® was used at stages R1, V6+R1 e R1+R5, followed by Daconil®, for the R1, V6+R1 e R1+R5 application times. The number of legumes produced by plant was altered significantly in function of the tested treatments. The application times and the tested fungicides provided significant alterations in grain productivity. The application of Opera® at the various times and Cerconil® at R1+R5 was responsible for the largest yields. The largest productivity was obtained with the use of the Opera® fungicide. The better application times were R1 (flowering onset) and R5 (onset of grain formation). The two application system did not show to be advantageous.